Check your springs / suspension
New (January 2014) Keystone Laredo 315 RE. 7500 dry, 9500 max, 1000 tongue.
About 1000 miles on it since "new".
Annual wheel bearing repack.
Curb side front leaf spring flat, other 3 spring packs various stages of cracked and broken.
Replacing all 4 with 5 leaf (had 4 leaf), replacing bolts with wet, all new hanger U Bolts, shackle bolts etc, both axles (4.4k) replaced with 6k Dexter.
Only good thing about the repack were the bearings were actually packed with grease as they should have been.
About $4k for new heavier springs, hardware, and axles.
From what I am reading this is more common than we would like to think that the suspension system is carrying maximum design weight right from the start.
2014 Chevy 2500HD
2014 Keystone Laredo 314RE